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Topic: CNC router VS 3D printer (Read 2306 times)

Hey, I am a 13 year old robot maker and I want to know which tool is better for me. right now I do my robots by hand in a band saw and with my drill press. I want to buy something around $1000-$1500 and I was thinking of a 3d printer or a CNC router. I need some hlep and tips to decide.

I can't say which would be better emphatically since I'm not sure what you would like to do specifically with either machine, but I can give you some insight so that you can make a decision.

3d printer:

Overview:

In your price range you would be looking at an FDM type machine (extruded ABS, PLA etc.). Having used some lower end machines in this price range my advice would be to look for a printer that has the best overall quality vs size of build platform. I spent so many hours tuning and tweaking my last low end printer. Also many of the low end machines boasting large build platforms miss a major point. You cannot make large prints especially out of ABS without a thermal chamber. Its a complicated process, but its mostly due to the contraction of the plastic as it cools. Some folks love tweaking and playing with these printers, but I just wanted to build stuff I could use. 20/20 hindsight proved I would have been better served using Shapeways, which is a great option by the way.

Despite my feelings about experience with some of the low end machines, consumer grade printers have advanced a lot. The Makerbot Replicator Mini looks to be a quality machine in your price range. They apparently addressed many of the typical annoyances (putting it lightly) such as leveling of the build platform. If I were to go with a 3d printer in your price range, that would be my pick.

Advantages to the technology:

With a 3d printer you can make fairly complex parts, that would in many cases be impossible for a 3 axis router to build.

3d printers are for the most part fully automated. You just press print, and come back in a few hours.

Disatvantages to the technology:

Repeatablily- lots of printers in this price range can be irritable. If you print the same thing multiple times you will probably notice some variances.

Its an additive process. So you need to factor in the cost of filament into your budget. Its typically more expensive than raw materials you would cut with a CNC.

Maintenance- to keep a printer running smoothly you need to make sure the extruders are not getting clogged; the build platform is level and clean so on and so forth

limited material selection- Some parts you may want to build will not be well suited for the materials you can print with

Grain boundaries- When you print layer by layer there is a defined grain to the part similar to a piece of wood. If you load an RP parallel with the grain it will be more prone to shearing along the grain.

CNC router:

Overview:

A CNC router is a powerful tool, that is really optimized for 2 1/d work. Meaning you can cut 2d shapes out of a block of material. The 1/2 d being a plunge of a given depth. That being said it is possible to create full 3d cuts, but this requires a range of tooling, and more advanced software, that may or may not be available in your price range. Be aware that many routers at the low end cut corners with build materials. Try to stay away from routers built from materials such as masonite manufactured wood and particle board, since these materials are highly sensitive to moisture, which causes warping. You may be able to treat or coat such materials to better weatherize them, but this could also disrupt the fit of the parts, which is bad too.

One of the biggest differences from 3d printing to routing is that you have to be aware of the cutting tool limitations. In the case of a router, milling of the material constitutes horizontal cuts with a rotating blade of some diameter. You cannot cut a square hole with a drill bit that you would put in a cnc router. So you need to think in terms of what features are reasonable or possible for the machine to make. 3d printers don't really suffer from this issue since they extrude minuscule amounts of material layer by layer. As such the extruder is always above the work piece.

Advantages:

generally have a larger build area (l x w) than 3d printers of the same expense

Vast material selection

More repeatable than FDM 3d printers (in my opinion)

Generally better resolution than comparable 3d printers

Disadvantages:

Tooling- all the drills and routing bits. You have to be careful when you design not to require exotic features that would require equally exotic tooling

Wear- The tooling used has a finite life span. As the tools become dull you need to replace them. Worn tools can break and produce poor results.

Tool changes- routers require different tools for different features when cutting in 3d. You have to babysit these machines to change out tooling.

Noisy

produces lots of debris

Closing:

If I were in your shoes, and wanted to make robot chassis I would consider what kinds or parts were important to me. If you want to make cool/intricate 3d parts I would go 3d printer or shapeways. If my goal was to make larger, and more robust parts, that were primarily 2d in nature, a CNC router would be the way to go.

Any router in that price range is not going to be a very robust machine. I wouldn't count on a router being able to cut metal even aluminum. While i'm sure you could do it with a well built router in a pinch, a mill is much more well suited to machining. Also, machining is much more complex than just pressing start you must consider many aspects such as work-holding, tooling, feeds and speeds, etc. Without a good understanding of machining practices anything beyond flat plates will likely prove challenging especially without the right tool (the right tool being a mill). And if all you are gong to be making is flat plates i don't think it is offering very much value. You can make some nice brackets and frame plates with a hacksaw, some files, and a drill press. If you take your time and use layout lines most people wouldn't be able to tell the difference between a milled and hand made plate. ...i know making the parts by hand doesn't sound like as much fun tho.

I think a 3D printer will offer you a lot more value in terms of what parts you are capable of producing. As mentioned, considering Shapeways as a source for these parts is a valid approach. They will be able to print higher quality and more precise parts than you without the investment cost. But I do understand the allure of having your own machine (it is kind of like a robot that makes robots ). For a 3D printer I would not go with Makerbot, as I have heard some negative things about their products and business practices. In my opinion the hobby level 3d printer technology is still developing and nobody has a perfect solution yet ... so you should expect to have to do some tinkering to get good performance. With that in mind I would chose a printer that supports user development and has a strong support community. I have been looking at buying an Ultimaker the version one is probably in your price range. I don't love their mechanical design, but that said i haven't found a hobby level printer that I wouldn't change something about their mechanics.

Hey, I am a 13 year old robot maker and I want to know which tool is better for me. right now I do my robots by hand in a band saw and with my drill press. I want to buy something around $1000-$1500 and I was thinking of a 3d printer or a CNC router. I need some hlep and tips to decide.

The 3D printer will do a LOT mrs then a router. It can make very complex parts. But do NOT buy a 3D printer until AFTER you have proved to yourself you can design parts. Simply send the STL file off to a service and then after you are making quite a few of them and like the results buy the printers This lets you learn what kind of a printer you want. What kind of materials work best and what sizes and precision do you need. Figure this out using Shapeways or the like